Innervation of the female internal genital organs: Whole-mount immunohistological observation in Suncus murinus

The musk shrew, Suncus murinus, is a unique animal model for the study of female behavioral endocrinology, and by utilizing the physiological characteristics of ovulation during mating of S. murinus, key progress has been made in the study of the endocrine regulatory function of the ovary. The study of innervation of the ovary of S. murinus is particularly important. In the present study, the 3-dimensional structure of the neural innervation of the internal genital organs of S. murinus (n=11, female) was studied using whole-mount immunohistochemical staining with neurofilament protein antibodies. The innervation of the ovary in S. murinus contains the superior ovarian nerve, which runs along the suspensory ligament of the ovary, and the ovarian plexus nerve, which runs along the ovarian artery and vein. The innervation of the uterus originates from the lower hypogastric plexus running in the pelvic peritoneum and along the uterine artery and vein. There was abundant communication between the ovarian plexus nerve and the lower hypogastric plexus of the pelvic peritoneum. The present study is the first to visualize the (NFP-positive) innervation of the female internal genital organs of the experimental animal S. murinus by the whole-mount immunohistochemistry method. The abundant communication between the ovarian plexus nerve and the lower hypogastric plexus of the pelvic peritoneum provides an additional pathway for the neural regulation of the ovary.